Page 377 - Geology and Geochemistry of Oil and Gas

338 APPENDIX C

fluid (oil and/or water) withdrawal from the oil/gas-
and water-producing formations.
Subunconformity Position of strata beneath an unconformity.
Sucrosic General, non-genetic term for coarse crystalline
texture, used mostly in reference to dolomites; a
porosity term referring to intercrystalline pores within
coarse crystalline dolomites.
Sulfuric acid karst Dissolution, generally of carbonate strata, by sulfuric
acid generated from the oxidation of upward
migrating, H 2 S-bearing fluids from depth.
Supraunconformity Position of strata directly above an unconformity.
Surface lift Any lifting equipment at the surface such as a
pumping unit.
Surface tension The tendency of liquids to maintain as small a surface
as possible. It is caused by the cohesive attraction
between the molecules of liquid.
Surfactant A soluble compound that concentrates on the surface
boundary between two substances such as oil and
water and reduces the surface tension between them.
The use of surfactant permits the thorough surface
contact or mixing of substances that ordinarily
remain separate. Surfactants are used in the
petroleum industry as additives to drilling mud and to
water during chemical flooding or well stimulation.
Swabbing Raising and lowering rubber cups in the tubing to
recover liquids.
Sweet gas (or crude oil) Gas or crude oil devoid of hydrogen sulfide and
carbon dioxide.
Syndepositional Physical, biologic, or diagenetic processes occurring
during sediment deposition. Syn: Synsedimentary.
Synergistic effect The added effect produced by two processes working
in combination. It is greater than the sum of the
individual parts.
System Generally, anything formed of parts placed together
or adjusted into a regular or connected whole.
Systems analysis Complete analysis of all phases of behavior of a
system, and development of a detailed procedure for
all collection, manipulation and evaluation of data
associated with the activity of all parts of the system.
Systems approach A sophisticated philosophy and a scientific method
for investigation through mathematical modeling
(simulation) of very complicated dynamic systems,
which cannot be modeled through material or
physical procedures, and which assumes that the
given feature is an integrated assembly consisting of